Steam cylinder oil and process of preparing the same



Patented June 22, 1937 PATENT OFFICE STEAM CYLINDER OIL AND PROCESS OF PREPARING THE SAME Arthur Lazar, Associated, and Joseph V. Crenna, Concord, Calif., assignors to Associated Oil Company, San Francisco, Calif., a corporation of California No Drawing. Application October 31, 1930, Serial No. 492,615. Renewed February 25, 1936 12 Claims.

This invention relates to the treatment of lubricating oil to insure stability under conditions of high temperatures and pressures in the presence of steam and has for a particular object the preparation of a lubricating oil especially adapted to function in the cylinders of steam engines.

In the manufacture of steam cylinder oils certain specifications must be strictly adhered to because of operating conditions peculiar to the uses of such oils.

Steam cylinder oils may not be suppliedvto the walls of the pistons and cylinders of the engine in many of the well-known forms of lubrication, but are introducedto the cylinder with the steam in such fashion that they are finely divided by atomization, whereby they are spread evenly over the moving parts.

In modern steam engine'practice the'temperature of the steam in the cylinder of the engine when closed by the piston goes as high as 500 F.

.under its corresponding pressure, and under such conditions it is highly important not only that a proper distribution of the oil is assured, but also that the stability of the oil is such as to resist decomposition, whereby undesirable deposits. such as coke, and the like, are eliminated.

Oils which have a tendency. to emulsify with steam are best suited for steam cylinder oils and heretofore it has been common practice to compound with a mineral oil a certain percentage of a fatty oil, such as tallow, which causes emulslfication. Such fatty oil, or oils, usually represent up to 8% to 10% of the mineral oil, but in addition to being costly, are decomposed at high temperatures which do not ail'ect the mineral oil hydrocarbons, thus forming free fatty acids which attack metals under such temperature conditions.

This invention provides a way of insuring the stability of steam cylinder oils while emulsifying the same under operating conditions, which is preferably accomplished in the following manrated hydrocarbons may also be prepared by extensive sulphuric acid treatment, or even distilled from certain stocks, such as Pennsylvania crudes.

To such stable lubricating oil is added a trace of a lime or magnesium soap of an organic acid, such, for example, as oleic acid, stearicacid, naphthenic acid, or sulphonic acid, the proportion of such added soap ranging in very small percentages of the oil, preferably from .01% to .1%.

While the above-mentioned soaps are preferred, the use of minute quantities of other soaps is effective to give emulsifying properties to lubricating oils, the percentages being such that the amount of ash arising from their use as emulsifiers is generally too small to be determined analytically.

This use results in a steam cylinder oil of unimpaired stability which emulsifles sufllciently to get the desired distribution, the soaps being easily combined with the saturated hydrocarbons, due to their oil solubility.

Likewise, a steam cylinder oil having the required emulsifying properties may be prepared from oils which result from the distillation of a suitable crude stock and which may be naturally composed mainly of saturated hydrocarbons. For instance, residual oils of Pennsylvania origin are found to contain organic acids in sumcient quantities that when traces of oxides, or hydroxides, are added to the oil when heated, such oil develops the desired pronounced emulsifying properties.

A preferred amount of magnesium oxide, or lime, or other alkaline earth oxide, or hydroxide, which may be added to such residual oil varies from .01% to .1%, and such is incorporated in the oil by intimate mixing at elevated temperatures, preferably about 300 F., and generally in excess of atmospheric temperatures. This oil may then be used as straight steam cylinder oil, or may be blended in amounts of from 10% to 20% withabodyofahighlyreflnedoilofhigh stability, such as the 80: treated oil previously described.

While it is unnecessary, the use of small mounts of an acidless fatty oil with the steam cylinder oils prepared as above described, has sometimes a beneficial effect in lowering the surface tension, but the quantity used, from 0% to 3%, is kept as low as possible and in any event We claim as our invention:

1. A process of preparing a steam cylinder oil which comprises: mixing a hydrocarbon lubricating oil and its normally contained organic acids with suflicient alkaline earth metal oxide to cause emulsification of the mixture when subjected to the action of direct steam but without liberation of free fatty acids or formation of ash at the temperature of emulsification; the amount of oxide being not more than 0.1% of theoil.

2. A process of preparing a steam cylinder oil which comprises: mixing a hydrocarbon lubricating oil and its normally contained organic acids at a temperature of the order of 300 F.

,with suflicient adkaline earth metal oxide to cause emulsification of the mixture when subjected to the action of direct steam but without liberation of free fatty acids or formation of ash at the temperature of emulsification; the amount of oxide being not more than 0.1% of the oil.

3. A process of preparing a steam cylinder oil which comprises: mixing a hydrocarbon lubrieating oil and its normally contained organic acids with suflicient alkaline earth metal hydroxide to cause emulsification of the mixture when subjected to the action of direct steam but without liberation of free fatty acids or formation of ash at the temperature of emulsification; the amount of oxide being not more than 0.1% of the oil.

4. A steam cylinder oil comprising: a residual oil suitable for lubricating oil and its normally contained organic acids in which from .01% to 0.1% of an alkaline earth metal oxide has been dissolved suflicient to saponify said organic acids.

5. A steam cylinder oil comprising: a body of hydrocarbons having a viscosity suitable for steam cylinder lubrication mixed with from 10% to 20% of a residual oil having the characteristics of Pennsylvania residual oil; said residual oil having its normally contained organic acids combined with from 0.01% to 0.1% of an alkaline earth metal oxide.

6. A steam cylinder oil comprising: a body of saturated hydrocarbons having a viscosity suitable for steam cylinder lubrication mixed with from 10% to 20% of a residual oil having the characteristics of Pennsylvania residual oil; said residual oil having its normally contained organic acids combined with from 0.01% to 0.1% of an alkaline earth metal oxide.

7. A steam cylinder oil comprising: a hydrocarbon lubricating oil of suitable viscosity for steam cylinder lubrication containing an alkaline earth metal derivative of organic acids normally present in petroleum in such amount that the metal of the derivative when calculated as oxide varies in amount between 0.01% and 0.1% with respect to the oil.

8. In the lubrication of the cylinders of steam engines, the improvement which comprises: com+ mingling with the steam supplied to such cylinders; a hydrocarbon lubricating oil having its normally contained organic acids combined with from 0.01% to 0.1% of an alkaline earth oxide sufiicient to cause emulsification of said oil when introduced into said cylinders but without substantial formation of decomposition products at the temperature of such emulsification.

'9. In the lubrication of the cylinders of steam engines, the improvement which comprises: commingling with the steam supplied to such cylinders, a body of saturated hydrocarbon oil containing from 10% to 20% of hydrocarbon oil having its normally contained organic acids combined with from 0.01% to 0.1% of an alkaline earth oxide suflicient to cause emulsifieation of said oil when introduced into said cylinders but without substantial formation of decomposition products at the temperature of such emulsification.

10. A steam cylinder oil comprising a hydrocarbon lubricating oil substantially free of organic acids and of viscosity suitable for steam cylinder lubrication containing from 0.01% to 0.1% of an alkaline earth metal soap of organic acid normally present in petroleum; said oil being capable of emulsification with direct steam in the cylinder of a steam engine up to temperatures as high' as-500 F. without decomposition of said soap.

11. A steam cylinder oil comprising, a residual oil suitable for lubricating oil and its normally contained organic acids in which from 0.01% to 0.1% of calcium oxide or hydroxide has been dissolved sufiicient to saponify said organic acids.

12. A steam cylinder oil comprising: a residual oil suitable for lubricating oil and its normally contained organic acids in which from 0.01% to 0.1% of magnesium oxide or hydroxide has been dissolved suflicient to saponify said organic acids.

ARTHUR. LAZAR. JOSEPH V. CRENNA. 

